Cataract and Glaucoma Case Detection for Vision 2020 Programs in Africa

PURPOSE: To determine if there is a screening test or a combination of screening tests that may be suitable for cataract and glaucoma case detection in Vision 2020 programs in Africa. METHODS: Design-Screening methods validation study. Setting-Groote Schuur Hospital, Cape Town, South Africa. Subjects-African patients aged 40 years and older with known cataract or with known glaucoma, and accompanying relatives aged 40 years and older with no known eye pathology. Outcome measures-Sensitivity, specificity, positive and negative likelihood ratios, and accuracy of 6 screening tests, used alone and in various combinations. RESULTS: Testing the pinhole visual acuity using a cut point of 6/18 in 1 or both eyes has a sensitivity and specificity greater than 90%, a positive likelihood ratio greater than 10.0, a negative likelihood ratio less than 0.1, and an accuracy greater than 90% for case detection of cataract or glaucoma. Examination of the optic disk with a lens free direct ophthalmoscope using a cut point of 0.7 for the vertical cup:disk ratio combined with testing for an afferent pupil defect has similar values for case detection of glaucoma. CONCLUSIONS: These tests may be suitable for use in Vision 2020 programs in Africa.